The Oliver technique for microdissection of the nephron is utilized in the pursuit of three objectives: The study of the architectonics of human kidneys and rat kidneys with special reference to the configuration and distribution of the loops of Henle. The study of experimental animal models of renal malformations, including several which display polycystic disease. To maintain a resource for the microdissection of selected diseased kidneys from infants and children, particularly ones representing hereditary nephropathies, and to provide facilities for the training of others in the microdissection technique.